Arguably true with Kate and we haven't seen Earth 2 Sawyer's story yet. But regarding the other ones we've seen:
claire - ended up keeping her son and seems glad she did
locke - wheel-chaired but accepts it, has a job he likes and a MILFy fiance/wife
jack - not a drunk, has started getting past his dead dad and is working it out with his son.
sayid - love of his life still alive, has a family and a job that doesn't involve killing people for Ben Linus.
